Backdoor.Linux.TSUNAMI.YXBLM

This Backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It connects to Internet Relay Chat (IRC) servers. It executes commands from a remote malicious user, effectively compromising the affected system.

Arrival Details

This Backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This Backdoor drops the following files:

• .bawtz -> Used as mutex

It drops the following copies of itself into the affected system:

• /dev/shm/{Malware Filename}
• /var/tmp/{Malware Filename}
• /var/lock/{Malware Filename}
• /var/lock/{Malware Filename}
• /root/{Random Characters}

It adds the following processes:

• /bin/uname
• /bin/nvram or /usr/sbin/nvram
• /etc/ISP_name
• /etc/Model_name

Backdoor Routine

This Backdoor connects to any of the following Internet Relay Chat (IRC) servers:

• {BLOCKED}.{BLOCKED}.155.72
• {BLOCKED}.{BLOCKED}.165.21
• {BLOCKED}.{BLOCKED}.230.55

It joins any of the following IRC channel(s):

• #redis

It executes the following commands from a remote malicious user:

• PAN - Performs an advanced SYN flood to a specific target at n seconds interval.
• UDP - Performs a UDP flood to a specific target at n seconds interval.
• HTTP - Perform a HTTP flood.
• STD - Triggers the bot to perform a denial of service (DoS) attack and also allows user to specify .
• UNKNOWN - Another non-spoof udp flooder
• KILL - Kill the running client.
• KILL_PORT - Kill a listener socket.
• GET - This downloads from and saves a file.
• SSHX <192 or 192.168 or 192.168.0> - Perform a SSH scan with provided credentials.
• SSH <192 or 192.168 or 192.168.0> - Perform a SSH scan.
• KILLALL - Kill all current packeting.
• HELP - Displays this.
• CBACK - Connect back to .
• IRC - Send commands to the IRC server.
• SH - Execute shell commands.

Information Theft

This Backdoor gathers the following data:

• Username
• Network Information
• Operating System Information
• Kernel Version
• System Hardware

Other Details

This Backdoor does the following:

• Adds the following crontab entries to enable its automatic execution at every minute:
  • crontab * * * * * /{Malware Path}/{Malware Filename}> /dev/null 2>&1 &
  • crontab * * * * * /{Copy Path}/{Malware Filename}> /dev/null 2>&1 &
• It does not continue with its routines if the following processes are running:
  • strace
  • tcpdump